Telescoping mast assembly

ABSTRACT

A rigid drive assembly for a telescoping mast is comprised of a pair of flexible link chains disposed at right angles to one another with respect to the pivot axes of the chain links and provided with interengaging latching elements which rigidly interconnect the two chains for movement along a linear path to extend and retract the mast. The two chains are spaced apart, and the latching elements interengage in the space between the two chains and include a plurality of latching plates on one of the chains extending transversely of the path and having openings therethrough in the direction of the path, and a pair of driving latch members for each latch plate engaging opposite sides of the latch plate and having a finger extending into the opening thereof.

BACKGROUND OF THE INVENTION

The present invention relates to the art of telescoping masts and, moreparticularly, to an improved interlocking or latching arrangementbetween driving and driven flexible link chains which provide a rigiddrive assembly for extending and retracting the mast sections.

A telescoping mast and rigid drive assembly of the character to whichthe present invention relates is illustrated and described in detail inU.S. Pat. No. 5,102,375 assigned to the same assignee as the presentapplication, and the subject matter of which patent is herebyincorporated by reference herein. Basically, the foregoing patentdiscloses a telescoping mast comprised of a plurality of nested mastsections adapted to be extended and retracted through a rigid driveassembly constructed of two flexible link-type chains, one of which isthe driving element of the assembly and the other of which is a drivenchain. The driving and driven chains have a common end connected to theinnermost mast section, and the two chains are disposed adjacent oneanother within the mast sections and at right angles to one another withrespect to the pivot axes of the links of the two chains. The two chainsare fed from corresponding storage positions to a location at which theybecome parallel for movement together along a linear path generallycoaxial with the mast sections and, at the point of linearity, the twoflexible chains are latched together so as to provide a rigid driveassembly movable along the linear path to achieve extension andretraction of the mast sections.

In the foregoing patent, the latching arrangements are provided bydriving plates secured, such as by welding, across the link plates ofadjacent links of the driving chain so as to have abutting edges whenthe links are in a linear disposition, and alternate ones of the drivingplates are provided with notches which are open toward the driven chainof the drive assembly. The link plates of the driven chain which facethe driving chain are provided with protrusions secured thereto such asby welding, and extending toward the driving plates, and alternate onesof the protrusions are notched in the direction of movement of the driveassembly for interengagement with the notches in the driving plates whenthe two chains reach the point of linearity. The others of theprotrusions on the links of the driven chain abut against the planarface of the driving plates when the two chains reach the point oflinearity. The interengaging notches of the driving plates andprotrusions rigidly interengage the two chains against separationlaterally of the path of movement and against flexure of the two chainsrelative to their link axes. The interengagement further provides forthe driving chain to displace the driven chain in opposite directionsalong the path of movement. The protrusions on the driven chain whichabut against the drive plates add stability against flexure of thedriving chain laterally of the path of movement.

While a latching arrangement of the foregoing character provides anadequate interconnection between the two flexible chains to provide arigid drive for extending and retracting the sections of a telescopingmast, the notching of the protrusions extending from the driven chainimposes limitations on the load which can be displaced by the driveassembly and, thus, the load which can be utilized in connection withthe mast. Furthermore, the welding of the notched drive plates to thedriving chain link plates and/or the welding of the protrusions to thelink plates of the driven chain is time consuming and expensive inconnection with the manufacture of the two chain members. Even if theprotrusions are integral with the driven chain link plates and thenotched driving plates are integral with the link plates of the drivingchain, the provision of such special link plate configurations togetherwith the notching of the protrusions and drive plates is still anexpensive procedure and does not overcome the load limitation imposed bythe notches in the protrusions on the driven chain. Still further, ifone of the notched protrusions or notched driving plates is damagedduring use of the drive assembly, replacement thereof is time consumingand difficult and requires disassembly and replacement of at least oneentire link section of either or both the driving and driven chains.Accordingly, an inventory of special link sections for both the chainsmust be maintained for repair and replacement purposes.

SUMMARY OF THE INVENTION

In accordance with the present invention, an improved link chainconstruction is provided and an improved latching arrangement isprovided between the flexible driving and driven link chains to form arigid interconnection therebetween and a rigid drive assembly havingimproved load capability and a reduced cost of construction and assemblyof the driving and driven chain members. Furthermore, the latchingarrangement according to the present invention advantageously providesfor latching components on the driving and driven chains to be removedand replaced without disassembly of link sections of the chains andwithout requiring different link constructions for such replacement.

More particularly in accordance with the present invention, the drivingand driven link chain members are provided with corresponding latchmember attachments mounted on the link plates of the two chains, such asby rivets, which enable the individual latch members to be removed andreplaced if necessary. Furthermore, the use of individual latch membersenables the chain link plates to be of identical construction for boththe driving and driven chain, whereby it is not necessary to maintaindifferent basic link constructions for the driving and driven chainmembers. More particularly in this respect, the chain link plates ofeach of the driving and driven chain members can be provided withintegral, outwardly extending flanges which are identical for bothchains and to which the corresponding latch member is readily removablysecured such as by riveting as mentioned above. Accordingly, only asingle basic link structure is necessary to make repairs to both chains.

Preferably in accordance with the invention, the driven chain isprovided with driven plate elements which extend into the space betweenthe two chains and which are captured in the direction of the linearpath of displacement of the drive assembly by a pair of latching memberson the driving chain. Preferably, the driven plate is provided with anopening in the direction of the path of movement, and one of the drivingmembers is provided with a finger which enters the opening andinterengages therewith to optimize stability against displacement of thetwo chains laterally of the path of movement thereof. In any event,should it become necessary to remove and replace any of the latchcomponents, it is only necessary to remove the rivet connection betweenthe latter and the corresponding chain, and rivet a new latch member inplace.

It is accordingly an outstanding object of the present invention toprovide an improved linearly displaceable drive assembly comprised oftwo interlocked flexible link chain members.

Another object is the provision of a drive assembly of the foregoingcharacter wherein the two link chain members are interlocked by alatching arrangement which provides improved load handling capabilityfor the drive assembly provided by the interlocked chain members.

Yet another object is the provision of a drive assembly of the foregoingcharacter wherein the driving and driven link chain members areselectively constructed from a basic link chain structure by mountingeither driving or driven latch components thereto.

A further object is the provision of a drive assembly of the foregoingcharacter wherein the driving and driven latch components are removablymounted on the corresponding driving or driven link chain member, thusfacilitating removal and replacement thereof.

Still a further object is the provision of a drive assembly of theforegoing character wherein the driving and driven link chain membersare structurally simple, economical to construct and maintain andefficient in use.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing objects, and others, will in part be obvious and in partpointed out more fully hereinafter in conjunction with the writtendescription of a preferred embodiment of the invention shown in theaccompanying drawings in which:

FIG. 1 is an elevation view, partially in section, showing a telescopingmast assembly incorporating a rigid drive assembly in accordance withthe present invention;

FIG. 2 is an enlarged elevation view in section showing a portion of thedriving and driven chain members in latched and unlatched relationship;

FIG. 3 is an enlarged sectional elevation view of the driven chain,member taken along line 3--3 in FIG. 2;

FIG. 4 is a cross-sectional view of the latched chain members takenalong line 4--4 in FIG. 2;

FIG. 5 is a cross-sectional elevation view of the latched, chain memberstaken along line 5--5 in FIG. 4;

FIG. 6 is an elevation view partly in section of the latched chainmembers as seen in the direction of line 6--6 in FIG. 4;

FIG. 7 is an elevation view partly in section of the latched chainmembers as seen in the direction of line 7--7 in FIG. 4; and,

FIG. 8 is a perspective view of a portion of the latched driving anddriven chain members.

DESCRIPTION OF A PREFERRED EMBODIMENT

Referring now to the drawings wherein the showings are for the purposeof illustrating a preferred embodiment of the invention only, and notfor the purpose of limiting the invention, FIG. 1 illustrates avertically extendable and retractable mast assembly 10 mounted on asuitable support S, such as a truck for example. Mast assembly 10 iscomprised of a plurality of telescoping mast sections 12, 14 and 16, thelowermost section 12 being suitably secured to support S and theuppermost section 16 carrying an antenna or the like 18 which is to beelevated and lowered by the mast assembly. While mast assembly 10 isshown in FIG. 1 as being comprised of three sections, this is forpurposes of simplicity, and it will be understood that the mast assemblycan include more sections than illustrated. Mast sections 12, 14 and 16are of tubular construction and have flanges 20 and 22 which interengageto limit relative displacement between the sections in the direction ofextension of the mast assembly.

The mast sections, and thus antenna 18, are adapted to be elevated andlowered relative to support S along a vertical path P by a rigid driveassembly comprising a driving chain member 24 and a driven chain member26 latchingly interengagable as described hereinafter. Each of the chainmembers 24 and 26 has an upper end connected to upper mast section 16such as by a head member 28 to which the chain ends are secured andwhich in turn is secured to a plate member 30 mounted in the lower endof section 16. As will be described in greater detail hereinafter, thedriving and driven chain members are each constructed from link platesspaced apart and interconnected by rollers providing axes about whichadjacent link sections are pivotal and, when the chain members arelatched together to provide a rigid, linear drive assembly within themast sections, the axes of the two chains are in planes perpendicular toone another.

Prior to displacement of the two chains into latching interengagement toprovide the rigid drive assembly along path P, the driving chain 24 iswound on a storage spool 32 having an axis parallel to the axes of therollers of the driving chain, and driven chain 26 is wound on a storagespool, not shown, and which is rotatable about an axis parallel to theroller axes of the driven chain. Driving chain 24 is adapted to bedisplaced in opposite directions relative to storage spool 32 and path Pby a drive sprocket 34 which is adapted to be rotated in oppositedirections by a suitable drive motor 36. Driven chain 26 extends aboutan idler sprocket 37 between its storage spool and path P. When sprocket34 is driven clockwise in FIG. 1, driving chain 24 is displaced fromspool 32 toward driven chain 26 and path P. As the link sections of thedriving chain move about the axis of sprocket wheel 34 they merge intoparallel relationship with the link sections of driven chain 26 movingabout the axis of sprocket wheel 37, and the two chains are latchinglyinterengaged as described hereinafter. Accordingly, driven chain 26 isdisplaced from its storage spool and upwardly by and together withdriving chain 24, and the interengaged chains provide the rigid driveassembly by which the mast sections are displaced toward the extendedpositions thereof by such upward displacement of the two chains. Uponreversing the drive of motor 36, the link sections of driving chain 24move out of latching interengagement with driven chain 26 in the areaadjacent sprocket wheels 34 and 37 and the driving chain is fed ontospool 32. Downward displacement of driving chain 24 imparts downwarddisplacement to driven chain 26 whereby, upon unlatching, the drivenchain is displaced into its storage area.

Referring now to FIGS. 2-8 of the drawing, it will be seen that each ofthe driving and driven chain members 24 and 26 is of the same basicconstruction with respect to the link plates and rollers thereof. Moreparticularly in this respect, each of the driving and driven chains isconstructed from alternating pairs of parallel inner link plates 38 andparallel outer link plates 40 which are laterally and pivotallyinterconnected at their overlapping ends by rollers 42 and correspondingroller pins 44 which extend through the rollers and through pin openingsin the link plates. Further, as will be appreciated from FIGS. 6 and 7,inner link plates 38 have opposite edges 38a and 38b between the endsthereof and outer link plates 40 have opposite edges 40a and 40b betweenthe ends thereof. Each inner link plate 38 of the driving and drivenchain members includes a flange 46 extending axially outwardly from edge38a thereof and provided with an opening 48 therethrough. Similarly,each of the outer link plates 40 of the driving and driven chain membersincludes a flange 50 extending axially outwardly from edge 40a thereofand having an opening 52 therethrough. Preferably, flanges 46 and 48 areintegral with the corresponding link plate, although the flanges couldbe separate therefrom and suitably secured thereto such as by welding.This basic structure for the driving and driven chains advantageouslyenables a single chain construction to be used interchangeably as thedriving or driven chain member, the only difference between the drivingand driven chain members being the components mounted thereon to achievedriving of the driven chain member and latching interengagement betweenthe driving and driven chain members for the latter to provide a rigiddrive assembly for the telescoping mast.

As best seen in FIGS. 2, 4, 5 and 8, driving chain 24 is provided withalternating first and second driving and latching members 54 and 56,respectively, mounted on adjacent link sections of the driving chainmember. Each of the first driving and latching members 54 is in the formof a plate and includes a body portion 58 and planar mounting flanges 60extending therefrom and overlying flanges 50 of outer link plates 40 ofeach of the link sections defined by the latter link plates. Each of thefirst driving and latching members is secured to the corresponding pairof flanges 50 by rivets 62 which facilitate assembly of the chain aswell as replacement of member 54 if it becomes necessary to do so. Bodyportions 58 extend into the space between the driving and driven chainmembers and, with respect to the vertical orientation of the driving anddriven chain members when latchingly interengaged, the flanges 60 ofeach of the first driving and latching members 54 have upper and lowerlinear edge surfaces 64 and 66, respectively. The upper end of bodyportion 58 is provided with a recess 68 defined at its outer end by anupstanding latching finger 70 which serves the purpose set forthhereinafter.

Each of the second driving and latching members 56 is in the form of aplate and includes a body portion 72 and planar mounting flanges 74extending outwardly therefrom and overlying flanges 46 of inner linkplates 38 of the corresponding chain section defined by the inner linkplates. As with members 54, each of the second driving and latchingmembers 56 is secured to the corresponding link flanges 46 by rivets 76.Flanges 74 of each second driving and latching member 56 have upper andlower linear edge surfaces 78 and 80, respectively. When the driving anddriven chains are latchingly interengaged, upper surface 78 abutsagainst lower surface 66 of the upwardly adjacent first driving andlatching member 54, and lower surface 80 abuts against upper surface 64of the first driving and latching member 54 therebeneath. Further, asbest seen in FIG. 5, the lower end of body portion 72 is coplanar withlower surface 80 and extends across the inner end of recess 68 in thefirst driving and latching member therebeneath for the purpose set forthmore fully hereinafter. As will be appreciated from FIG. 6, the bodyportions 58 and 72 of the driving and latching members 54 and 56 have awidth generally corresponding to the lateral spacing between inner linkplates 38 of the chain

As best seen in FIGS. 2, 4, 5 and 8, driven chain member 26 is providedwith a plurality of driven plate members 82, each of which is comprisedof a mounting plate portion 84 overlying flanges 46 and 50 of adjacentinner and outer link plates 38 and 40 of the driven chain member. Eachdriven plate member 82 is preferably secured to both the correspondingflanges 46 and 50 of adjacent chain links by rivets 86 extending throughopenings therefor in the mounting plate portion and openings 48 and 52in the link flanges. However, the mounting plate portion 84 can besecured to just flanges 46 or just flanges 50 in which case the mountingplate portion is displaceable relative to one pair of the flanges topermit pivotal movement between the adjacent links which is otherwiseprecluded. Again, the use of rivets facilitates construction of thechain as well as maintenance thereof. Each driven plate member 82further includes an L-shaped driven flange including a first leg 87integral with and extending perpendicularly from the edge of mountingplate portion 84 facing driving chain 24, and a second leg 88perpendicular to leg 87 and extending therefrom into the space betweenthe two chains. Flange leg 88 has upper and lower surfaces 90 and 92,respectively, perpendicular to the path of movement of the driveassembly, and the latter flange leg is provided with an opening 94between the upper and lower surfaces. Opening 94 receives finger 70 of afirst driving and latching member 54 on driving chain 24 when thedriving and driven chains are latchingly interengaged and has length andwidth dimensions closely corresponding to the length and width of finger70. Mounting plate portion 84 of each driven plate member 82 has upperand lower linear edge surfaces 96 and 98, respectively, and when the twochain members are latchingly interengaged, adjacent ones of the edges 96and 98 are in abutting engagement.

The thickness of flange leg 88 between surfaces 90 and 92 corresponds tothe depth of recess 68 in the first driving and latching member, and theleg 88 extends toward driving chain 24 in the recess to the extent thatthe outer end of the flange leg underlies the lower end of body portion72 of the adjacent second driving and latching member 56 on the drivingchain member. Thus, when the two chains are interengaged, leg 88 of thedriven flange is laterally captured in recess 68 by the interengagementbetween finger 70 and opening 94 and is vertically captured between thebottom of recess 68 and the lower end of body portion 72 of the upwardlyadjacent second driving and latching member. Accordingly, it will beappreciated that when driving chain 24 is displaced upwardly, drivenchain 26 is driven upwardly by the driving chain through theinterengagement of flange legs 88 with the first driving and clampingmembers and that, during driving displacement of chain 24 downwardly,the driven chain member 26 is driven downwardly by interengagement offlange legs 88 with the lower ends of body portions 72 of the seconddriving and latching members 56. Moreover, during both suchdisplacements of the driving and driven chain members, the driving anddriven latching members interengage to preclude relative lateraldisplacement between the two chain members in a plane transverse to thepath of movement and thus provide a rigid drive assembly by which thetelescoping mast can be extended and retracted. Rigidity of the assemblyis further promoted by the abutting engagement between adjacent members54 and 56 on chain 24 and adjacent members 82 on chain 26.

It will be appreciated from FIGS. 2 and 5 that the first and seconddriving and latching members on the driving chain member are orientedrelative to a corresponding driven plate member on the driven chainmember to provide for latching interengagement therebetween to takeplace smoothly as the link sections of the two chain members move fromtheir storage positions about the corresponding sprocket wheel and makethe transition to the vertical orientations thereof. More particularlyin this respect, as the first driving and latching members 54 move aboutthe axis of sprocket wheel 34 in the direction to drive the driving anddriven chain members upwardly, finger 70 of a driving and clampingmember and the adjacent recess 68 in the upper surface thereofprogressively move into interengaging relationship with opening 94 andthe lower surface 92 of flange leg 88 of a driven plate member 82. Thistransition of the driving and driven chain members from detached tolatched relationship further provides for the upper surface 90 of drivenflange leg 88 to engage the lower end of body portion 72 of the seconddriving and latching member 56 immediately ahead of the first latchingmember 54 with respect to the upward direction of movement of thedriving and driven chain members.

While considerable emphasis has been placed herein on a specificembodiment of the invention, it will be appreciated that otherembodiment as well as modifications of the embodiment disclosed will besuggested or apparent and can be made without departing from theprinciples of the invention. Accordingly, it is to be distinctlyunderstood that the foregoing descriptive matter is to be interpretedmerely as illustrative of the present invention and not as a limitation.

Having thus described the invention, it is claimed:
 1. In a driveassembly comprising a head member movable along a generally straightpath between first and second positions, driving and driven flexiblechain member means for moving said head member between said first andsecond positions and having corresponding first ends connected to saidhead member, said driving chain member means comprising driving linkmeans interconnected at pivot axes transverse to said path, said drivenchain member means comprising driven link means interconnected at pivotaxes transverse to said path and to said axes of said driving linkmeans, the improvement comprising: said driving and driven chain membermeans being disposed along said path to provide a space therebetween,said driven link means comprising driven flange means extending intosaid space, said driven flange means being spaced apart in the directionof said path and having opposite sides in said direction, said drivinglink means including driving member means drivingly engaging said drivenflange means in said space between said driving and driven chain membermeans, and said driven flange means and driving member means includinglatch means interconnecting said driving and driven chain members insaid space for movement together along said path.
 2. A drive assemblyaccording to claim 1, wherein said latch means includes openings throughsaid flange means between said opposite sides thereof and latchingfingers on said driving member means extending in said direction andreceived in said openings.
 3. A drive assembly according to claim 1,wherein said driving member means includes means for engaging saidopposite sides of said flange means.
 4. A drive assembly according toclaim 3, wherein said driving member means includes first and seconddriving members on adjacent driving link means and having opposed endmeans in said space between said driving and driven chain members, saidopposed end means engaging said opposite sides of one of said flangemeans therebetween.
 5. A drive assembly according to claim 4, whereinsaid latch means includes openings through said flange means betweensaid opposite sides thereof and a latching finger on one of said firstand second driving members received in the opening of said one flangemeans when said opposed end means engage said opposite sides thereof. 6.A drive assembly according to claim 5, and a plurality of telescopingmast sections nested within one another for movement by said driveassembly between said first and second positions wherein said mastsections are respectively retracted and extended, said head member beingconnected to the innermost one of said mast sections.
 7. A driveassembly according to claim 1, wherein each of said driven flange meansincludes a mounting plate secured to the driven link means of saiddriven chain member means parallel to the pivot axes of said driven linkmeans, said mounting plate having an edge facing said space between saiddriving and driven chain member means, and said flange means beingintegral with said mounting plate and extending into said space fromsaid edge.
 8. A drive assembly according to claim 7, wherein saiddriving member means includes first and second driving members onadjacent driving links and having opposed end means in said spacebetween said driving and driven chain member means, said opposed endmeans engaging said opposite sides of one of said flange meanstherebetween.
 9. A drive assembly according to claim 8, wherein the endmeans of one of said first and second driving members includes a recessproviding a finger in said space and extending in the direction of saidpath, said flange means including an opening therethrough receiving saidfinger, and said recess and the end means of the other of said first andsecond driving members engaging said opposite sides of said flange meanstherebetween.
 10. A drive assembly according to claim 9, and a pluralityof telescoping mast sections nested within one another for movement bysaid drive assembly between said first and second positions wherein saidmast sections are respectively retracted and extended, said head memberbeing connected to the innermost one of said mast sections.
 11. A driveassembly according to claim 1, and a plurality of telescoping mastsections nested within one another for movement by said drive assemblybetween said first and second positions wherein said mast sections arerespectively retracted and extended, said head member being connected tothe innermost one of said mast sections.
 12. A drive assembly accordingto claim 1, wherein said driving link means of said driving chain membermeans includes a plurality of pairs of parallel inner drive link platesseparated by a pair of drive rollers and a plurality of pairs of outerdrive link plates connecting adjacent inner drive link plates at saiddrive rollers, each said inner and outer drive link plate having an edgefacing said space and mounting flange means extending axially outwardlyfrom said edge with respect to the axes of said drive rollers, and saiddriving member means including first and second driving membersalternately mounted on the mounting flange means of said pairs of innerand outer drive link plates.
 13. A drive assembly according to claim 12,wherein said driven link means of said driven chain member means includea plurality of pairs of parallel inner driven link plates separated bydriven rollers and a plurality of pairs of outer driven link platesconnecting adjacent inner driven link plates at said driven rollers,each said inner and outer driven link plate having mounting flange meansextending axially outwardly therefrom with respect to the axes of saiddriven rollers, said driven flange means including a mounting platemounted on the mounting flange means of adjacent pairs of inner andouter driven link plates, said mounting plate having an edge facing saidspace, said driven flange means being integral with said edge of saidmounting plate and including a planar flange plate extending into saidspace.
 14. A drive assembly according to claim 13, wherein each of saidfirst and second driving members has opposite ends in the direction ofsaid path, the opposed ends of adjacent ones of said first and seconddriving members being in abutting relationship along said path, and oneend of each of said first driving members and the opposed end of theadjacent second driving member being profiled to provide a recesstherebetween.
 15. A drive assembly according to claim 14, wherein saidplanar flange plate extends into said recess between said one end ofsaid first driving member and said opposed end of said second drivingmember.
 16. A drive assembly according to claim 15, wherein said recessis provided in said one end of said first driving member and includes afinger extending in the direction of said path, said planar flange plateincluding an opening therethrough receiving said finger, and saidopposed end of said second driving member overlying a portion of saidplanar flange plate in said recess.
 17. A drive assembly according toclaim 16, and a plurality of telescoping mast sections nested within oneanother for movement by said drive assembly between said first andsecond positions wherein said mast sections are respectively retractedand extended, said head member being connected to the innermost one ofsaid mast sections.
 18. A drive assembly according to claim 12, whereineach of said first and second driving members has opposite ends in saiddirection of said path, the opposed ends of adjacent ones of said firstand second driving members being in abutting relationship along saidpath, and one end of each of said first driving members being profiledto provide a recess facing the opposed end of the adjacent second drivemember, and said opposed end of said second drive member partiallycovering said recess.
 19. A drive assembly according to claim 18,wherein said mounting flange means on said inner and outer drive linkplates are coplanar, each said first and second driving membersincluding a body portion and mounting plates extending integrally fromsaid body portion and overlying said mounting flange means, andremovable means connecting said mounting plates to said mounting flangemeans.
 20. A drive assembly according to claim 19, wherein said recessis in said body portion of said first driving member and said opposedend of said second driving member partially covering said recess isprovided by the body portion of said second drive member.
 21. A driveassembly according to claim 20 wherein said driven link means of saiddriven chain member means include a plurality of parallel inner drivenlink plates separated by driven rollers and a plurality of outer drivenlink plates connecting adjacent inner driven link plates at said drivenrollers, each said inner and outer driven link plate having mountingflange means extending axially outwardly therefrom with respect to theaxes of said driven rollers, said driven flange means including amounting plate mounted on the mounting flange means of adjacent innerand outer driven link plates and having an edge facing said space, saiddriven flange means being integral with said edge of said mounting plateand including a planar flange plate extending into said space.
 22. Adrive assembly according to claim 21, wherein said planar flange plateextends into said recess between said one end of said first drivingmember and said opposed end of said second driving member.
 23. A driveassembly according to claim 22, wherein said recess in said one end ofsaid first driving member includes a finger extending in the directionof said path and said planar flange plate includes an openingtherethrough receiving said finger, and wherein said opposed end of saidsecond driving member partially covering said recess overlies a portionof said planar flange plate in said recess.
 24. A drive assemblyaccording to claim 23, wherein said mounting flange means on said innerand outer driven link plates are coplanar and said mounting plates ofsaid driven flange means overlie said mounting flange means, andremovable means connecting the latter said mounting plates to saidmounting flange means.
 25. A drive assembly according to claim 24,wherein said driven flange means includes a first flange portion havinga first end integral with said edge of said mounting plate and a secondend spaced from said edge and parallel thereto, and a second flangeportion extending from said second end and providing said planar flangeplate.